Abstract Picophytoplankton, such as Prochlorococcus and Synechococcus, thrive in oligotrophic environments and contribute 60–80% of marine primary productivity. However, their role in the Bay of Bengal productivity remains insufficiently studied. We investigated the spatial and vertical distribution of picophytoplankton in the Bay during a spring intermonsoon. Seawater samples were collected from eight locations spanning coastal and open ocean regions, and picophytoplankton abundance, carbon biomass, and environmental correlations were examined. Somewhat contrary to previous studies, we found that Prochlorococcus thrived in both oligotrophic and nutrient-rich waters, exhibiting significant correlations with nitrite and temperature, while Synechococcus dominated the coastal zones, with abundance negatively correlated with salinity and nutrients. The average carbon biomass was 0.6 µg L−1 for Prochlorococcus and 1.3 µg L−1 for Synechococcus. Moreover, the carbon biomass contribution to particulate organic carbon ranged between 0.05 and 15%, highlighting the significant role of picophytoplankton in marine carbon cycling. Our findings underscore the adaptation of these groups to varying environmental conditions and their crucial ecological role in the Bay of Bengal. Our study provides valuable insights into the environmental factors shaping picophytoplankton dynamics and their contributions to biogeochemical processes, paving the way for further research into their region-specific adaptations. Research highlights <UnorderedList Mark="Bullet"> <ItemContent> Prochlorococcus abundance outnumbered Synechococcus abundance in the coastal and open Bay of Bengal. </ItemContent> <ItemContent> Prochlorococcus and Synechococcus carbon biomass contribution to particulate organic carbon ranging from 0.05% to 15% in spring intermonsoon. </ItemContent> <ItemContent> Temperature, nitrite and phosphate are key environmental factors affecting picophytoplankton in the Bay of Bengal. </ItemContent> <ItemContent> The study reveals region-specific adaptations and environmental factors shaping picophytoplankton dynamics. </ItemContent> </UnorderedList>

Picophytoplankton abundance and their contribution to particulate organic carbon in the Bay of Bengal

期刊论文
发表日期：

2026年2月27日

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Sipai Nazirahmed,
Deepika Sahoo,
Himanshu Saxena,
Arvind Singh,
Rakeshkumar R Panchal

摘要

Abstract

Picophytoplankton, such as Prochlorococcus and Synechococcus, thrive in oligotrophic environments and contribute 60–80% of marine primary productivity. However, their role in the Bay of Bengal productivity remains insufficiently studied. We investigated the spatial and vertical distribution of picophytoplankton in the Bay during a spring intermonsoon. Seawater samples were collected from eight locations spanning coastal and open ocean regions, and picophytoplankton abundance, carbon biomass, and environmental correlations were examined. Somewhat contrary to previous studies, we found that Prochlorococcus thrived in both oligotrophic and nutrient-rich waters, exhibiting significant correlations with nitrite and temperature, while Synechococcus dominated the coastal zones, with abundance negatively correlated with salinity and nutrients. The average carbon biomass was 0.6 µg L⁻¹ for Prochlorococcus and 1.3 µg L⁻¹ for Synechococcus. Moreover, the carbon biomass contribution to particulate organic carbon ranged between 0.05 and 15%, highlighting the significant role of picophytoplankton in marine carbon cycling. Our findings underscore the adaptation of these groups to varying environmental conditions and their crucial ecological role in the Bay of Bengal. Our study provides valuable insights into the environmental factors shaping picophytoplankton dynamics and their contributions to biogeochemical processes, paving the way for further research into their region-specific adaptations.

Research highlights

Prochlorococcus abundance outnumbered Synechococcus abundance in the coastal and open Bay of Bengal.

Prochlorococcus and Synechococcus carbon biomass contribution to particulate organic carbon ranging from 0.05% to 15% in spring intermonsoon.

Temperature, nitrite and phosphate are key environmental factors affecting picophytoplankton in the Bay of Bengal.

The study reveals region-specific adaptations and environmental factors shaping picophytoplankton dynamics.